A ceramic substrate and a power module

Abstract

This utility model relates to the field of ceramic substrate technology, and more particularly to a ceramic substrate and a power module. The ceramic substrate includes a functional area and an auxiliary area, with the auxiliary area disposed on the functional area. The functional area includes a first metal layer, a ceramic layer, and a second metal layer stacked sequentially. A microgroove cooling cavity is provided on the first surface of the second metal layer, and an injection mechanism connected to the microgroove cooling cavity is provided on the second surface of the second metal layer. The first surface of the second metal layer is the surface in contact with the ceramic layer, and the second surface of the second metal layer is correspondingly disposed to its first surface. The microgroove cooling cavity is used to fill a working fluid to achieve heat dissipation. The injection mechanism is used to seal the microgroove cooling cavity. This ceramic substrate is a high-heat-dissipation-efficiency ceramic substrate, improving the heat dissipation efficiency of the power module formed on the ceramic substrate, enabling the power module to meet the requirements of high load, small space, and low-cost operation and production.

Description

Technical Field

[0001] This utility model relates to the field of ceramic substrate technology, and in particular to a ceramic substrate and a power module. Background Technology

[0002] Power semiconductor devices, as core components for power conversion and control, need to withstand high voltage and high current while generating significant power losses, which are converted into heat. Integrating multiple power semiconductor devices into a single package according to a typical power electronic circuit topology forms a power semiconductor package module, or power module. The heat of a power module is mainly concentrated at the power semiconductor chip, requiring a good heat dissipation design to quickly and effectively dissipate heat to the surrounding environment to prevent damage from overheating. Heat dissipation performance directly affects the performance and reliability of the semiconductor package. Furthermore, with advancements in power semiconductor technology, the trends towards high-power, high-heat-flux-density chips and miniaturized, highly integrated package modules make heat dissipation an increasingly prominent issue for power modules.

[0003] Currently, power modules typically employ heat dissipation designs based on convection, radiation, and conduction. Convection heat dissipation involves conducting heat from the power semiconductor devices within the power module to the heatsink surface, where it is then dissipated into the environment through fluid convection. Radiation plays a relatively minor role in power module heat dissipation. Conduction heat dissipation is based on the design of the heat dissipation materials used in the power module. The efficiency of heat conduction depends on the thermal conductivity of the heat dissipation material and is also limited by its inherent thermal conductivity.

[0004] Furthermore, existing power module ceramic substrates primarily employ a sandwich structure using either Direct Copper Bonding (DBC) or Active Metal Brazing (AMB) ceramic substrates. This involves two metal layers with a ceramic layer sandwiched between them, and the upper metal layer containing the conductive lines. The main drawbacks of existing power module ceramic substrates are:

[0005] 1. The metal layer is thin and divided into small areas. The heat from the chip's heat source (mainly the IGBT chip, with a small amount of heat from the FRD chip) cannot be conducted laterally, but only vertically. The IGBT chip area occupies only about one-third of the substrate area. This results in a small effective heat transfer area, high thermal resistance (thermal resistance is inversely proportional to the heat transfer area), and high chip junction temperature.

[0006] 2. Large temperature differences between parallel chips lead to uneven current distribution and local failures, which in turn damage the power module.

[0007] Therefore, the current ceramic substrates and power modules of power modules have low heat dissipation efficiency. Utility Model Content

[0008] This application provides a ceramic substrate and a power module, which solves the technical problem of low heat dissipation efficiency of ceramic substrates and power modules in the prior art. It realizes a specific structure of a ceramic substrate with high heat dissipation efficiency, enhances the heat dissipation effect of the ceramic substrate, improves the heat dissipation efficiency of the power module formed on the ceramic substrate, and enables the power module to meet the requirements of high load, small space and low cost operation and production.

[0009] In a first aspect, this utility model provides a ceramic substrate, including: a functional area and an auxiliary area, wherein the auxiliary area is disposed on the functional area;

[0010] The functional area includes: a first metal layer, a ceramic layer and a second metal layer stacked in sequence; a microgroove cooling cavity is provided on the first side of the second metal layer; and an injection mechanism connected to the microgroove cooling cavity is provided on the second side of the second metal layer. The first side of the second metal layer is the side of the second metal layer that contacts the ceramic layer, and the second side of the second metal layer is correspondingly arranged with the first side of the second metal layer.

[0011] The auxiliary region is used for conducting current and signals;

[0012] The microgroove cooling cavity is used to fill the working fluid so that the microgroove cooling cavity can achieve the function of heat dissipation;

[0013] The injection mechanism is used to seal the microgroove cooling cavity.

[0014] Optionally, the thickness of the microgroove cooling cavity is not greater than the thickness of the second metal layer, and the microgroove cooling cavity is uniformly distributed on the first surface of the second metal layer.

[0015] Optionally, the width of the microgroove cooling cavity ranges from 0.2 to 0.8 mm, and the thickness ranges from 0.1 to 0.4 mm.

[0016] Optionally, the injection mechanism protrudes from the second surface of the second metal layer, penetrates the second metal layer, and is connected to the microgroove cooling cavity.

[0017] Optionally, the injection mechanism includes an inner hollow three-dimensional space and an outer three-dimensional space, wherein the outer three-dimensional space encloses the inner hollow three-dimensional space.

[0018] Optionally, the auxiliary region includes: a first auxiliary insulating layer, a first auxiliary conductive layer, a second auxiliary insulating layer, and a second auxiliary conductive layer located on the second metal layer;

[0019] The first auxiliary insulating layer is disposed between the second metal layer and the first auxiliary conductive layer, and is used for insulation and auxiliary heat conduction;

[0020] A first auxiliary conductive layer is disposed between the first auxiliary insulating layer and the second auxiliary insulating layer for conducting power current;

[0021] The second auxiliary insulating layer is disposed on the first auxiliary conductive layer and is used for insulation;

[0022] The second auxiliary conductive layer is disposed on the second auxiliary insulating layer and is used to conduct control signals and sampling electrical signals.

[0023] Optionally, the auxiliary region includes: a first auxiliary insulating layer, a first auxiliary conductive layer, and a second auxiliary conductive layer located on the second metal layer;

[0024] Both the first auxiliary conductive layer and the second auxiliary conductive layer are disposed on the first auxiliary insulating layer. The first auxiliary conductive layer and the second auxiliary conductive layer are located on the same plane. The second auxiliary conductive layer is disposed within the first auxiliary conductive layer. An electrical gap is provided between the first auxiliary conductive layer and the second auxiliary conductive layer to achieve electrical isolation between the first auxiliary conductive layer and the second auxiliary conductive layer.

[0025] Optionally, it also includes: a temperature acquisition area, which is located on the second surface of the second metal layer and is used to acquire temperature;

[0026] The temperature acquisition area includes: a temperature insulation layer and a temperature sampling metal layer;

[0027] The temperature insulation layer is located on the same plane as the auxiliary area;

[0028] The temperature sampling metal layer is disposed on the temperature insulation layer and is used to connect and install the thermistor and to perform temperature sampling.

[0029] Optionally, the microgroove cooling cavity is provided on the first side of the first metal layer, and the injection mechanism connected to the microgroove cooling cavity is provided on the second side of the first metal layer. The first side of the first metal layer is the side of the first metal layer that contacts the ceramic layer, and the second side of the first metal layer is correspondingly provided to the first side of the first metal layer.

[0030] Based on the same inventive concept, in a second aspect, this utility model also provides a power module, comprising: a ceramic substrate as described in the first aspect, and a power chip disposed on the ceramic substrate, power terminals and signal terminals of the power chip, an outer frame, a cover plate and encapsulating adhesive, wherein the power terminals and the signal terminals are connected to the power chip;

[0031] The cover plate is also disposed on the outer frame, and the ceramic substrate, the outer frame and the cover plate form a closed cavity so that the power chip is located in the cavity;

[0032] The encapsulating adhesive fills the sealed cavity;

[0033] The power terminal and the signal terminal pass through the cavity.

[0034] One or more technical solutions in the embodiments of this utility model have at least the following technical effects or advantages:

[0035] The ceramic substrate of this embodiment includes a functional area and an auxiliary area. The functional area includes a first metal layer, a ceramic layer, and a second metal layer stacked sequentially. A microgroove cooling cavity is provided on the side of the second metal layer that contacts the ceramic layer, and an injection mechanism connected to the microgroove cooling cavity is provided on the side of the second metal layer that does not contact the ceramic layer. The microgroove cooling cavity is used to fill a working fluid. The injection mechanism is used to seal the microgroove cooling cavity, forming a closed cavity. The ceramic substrate of this embodiment achieves the mutual conversion of thermal energy and mechanical energy based on the circulation of the working fluid in the microgroove cooling cavity, obtains work by relying on the state change of the working fluid, and transfers heat through the work done by the working fluid. In this way, the ceramic substrate makes full use of the extremely high heat transfer coefficient brought about by the phase change of the working fluid, and can quickly transfer the heat generated by electronic devices.

[0036] Furthermore, in this embodiment of the invention, the ceramic substrate, through the micro-groove cooling cavity, injection mechanism, and pulsating heat pipe formed by the working fluid, can laterally diffuse the heat from the power chip mounted on the ceramic substrate to the entire ceramic substrate plane, greatly increasing the effective heat transfer area. This significantly reduces the thermal resistance of the power module based on the ceramic substrate and also ensures uniform junction temperature distribution and current distribution of the power chip mounted on the ceramic substrate, improving the reliability of the power chip and power module. In addition, the phase change heat dissipation efficiency of the micro-groove cooling cavity of the ceramic substrate is significantly higher than that of existing metal thermal conductivity, significantly reducing the junction temperature of the power chip. At the same time, it reduces the temperature difference inside the power module, especially between the heat sources of the power chip, effectively reducing hot spot effects, facilitating current sharing among parallel power chips, improving the overall reliability of the power module, and giving the ceramic substrate and power module good temperature uniformity and high thermal conductivity. Thus, the power module can also adapt to the requirements of high load, small space, and low cost operation and production. Attached Figure Description

[0037] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference figures denote the same parts throughout the drawings. In the drawings:

[0038] Figure 1 An exploded view of the ceramic substrate in an embodiment of this utility model is shown.

[0039] Figure 2 This diagram shows a first structural schematic of the microgroove cooling trench in an embodiment of the present invention.

[0040] Figure 3 A schematic diagram of a second structure of the microgroove cooling trench in an embodiment of this utility model is shown;

[0041] Figure 4 A schematic diagram of a third structure of the micro-groove cooling trench in an embodiment of this utility model is shown;

[0042] Figure 5 A schematic diagram of the fourth structure of the micro-groove cooling trench in this embodiment of the present invention is shown;

[0043] Figure 6 This diagram shows a top view of the ceramic substrate in an embodiment of the present invention, viewed from the perspective of the second metal layer.

[0044] Figure 7 A schematic diagram of another structure of the ceramic substrate in an embodiment of the present invention is shown;

[0045] Figure 8 A schematic diagram of the microgroove cooling cavity of the first metal layer in an embodiment of this utility model is shown;

[0046] Figure 9 A partial structural schematic diagram of the power module in an embodiment of this utility model is shown.

[0047] In the attached diagram, 100 is the functional area; 200 is the auxiliary area; and 300 is the temperature acquisition area.

[0048] 110. First metal layer; 120. Ceramic layer; 130. Second metal layer; 140. Microgroove cooling cavity; 150. Injection mechanism; 151. Internal hollow three-dimensional structure; 152. External three-dimensional structure;

[0049] 210, First auxiliary insulating layer; 220, First auxiliary conductive layer; 230, Second auxiliary insulating layer; 240, Second auxiliary conductive layer;

[0050] 310. Temperature insulation layer; 320. Temperature sampling metal layer;

[0051] 410. Power chip;

[0052] 421, First power pin; 422, Second power pin; 423, Third power pin;

[0053] 431. Lower bridge gate terminal; 432. First lower bridge sampling terminal; 433. Second lower bridge sampling terminal; 434. Upper bridge gate terminal; 435. First upper bridge sampling terminal; 436. Second upper bridge sampling terminal; 437. Temperature sampling terminal. Detailed Implementation

[0054] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0055] Example 1

[0056] The first embodiment of this utility model provides a ceramic substrate, such as Figure 1 As shown, it includes a functional area 100 and an auxiliary area 200, with the auxiliary area 200 disposed on the functional area 100. The functional area 100 is used to carry the auxiliary area 200, which is used to conduct current and signals, such as assisting a power chip mounted on a ceramic substrate in conducting current and related signals.

[0057] Functional area 100 includes a first metal layer 110, a ceramic layer 120, and a second metal layer 130 stacked sequentially. A microgroove cooling cavity 140 is provided on the first surface of the second metal layer 130, and an injection mechanism 150 connected to the microgroove cooling cavity 140 is provided on the second surface of the second metal layer 130. The first surface of the second metal layer 130 is the surface that contacts the ceramic layer 120, and the second surface of the second metal layer 130 corresponds to the first surface of the second metal layer 130.

[0058] The first metal layer 110 is used to connect to the heat sink or heat sink. The ceramic layer 120 is used for insulation and thermal conductivity. The second metal layer 130 is used for electrical and thermal conductivity, such as conducting electrical signals and heat from the power chip mounted on the ceramic substrate. The microgroove cooling cavity 140 is used to fill the working fluid to achieve heat dissipation. The injection mechanism 150 is used to seal the microgroove cooling cavity 140. The working fluid is the active substance that achieves heat-work conversion, used in the thermodynamic system of the ceramic substrate to absorb, transfer, and release heat; it is a key substance for energy conversion.

[0059] The ceramic substrate of this embodiment includes a functional region 100 and an auxiliary region 200. The functional region 100 includes a first metal layer 110, a ceramic layer 120, and a second metal layer 130 stacked sequentially. A microgroove cooling cavity 140 is provided on the side of the second metal layer 130 that contacts the ceramic layer 120, and an injection mechanism 150 connected to the microgroove cooling cavity 140 is provided on the side of the second metal layer 130 that does not contact the ceramic layer 120. The microgroove cooling cavity 140 is used to fill a working fluid. The injection mechanism 150 is used to seal the microgroove cooling cavity 140, forming a closed cavity. The ceramic substrate of this embodiment achieves the mutual conversion of thermal and mechanical energy based on the circulation of the working fluid within the microgroove cooling cavity 140, obtaining work through the state change of the working fluid, and transferring heat through the work done by the working fluid. Thus, the ceramic substrate fully utilizes the extremely high heat transfer coefficient brought about by the phase change of the working fluid, enabling rapid heat transfer from electronic devices.

[0060] Furthermore, in this embodiment, the ceramic substrate, through the micro-groove cooling cavity 140, the injection mechanism 150, and the pulsating heat pipe formed by the working fluid, can laterally diffuse the heat from the power chip mounted on the ceramic substrate to the entire ceramic substrate plane, greatly increasing the effective heat transfer area. This significantly reduces the thermal resistance of the power module based on the ceramic substrate and also ensures uniform junction temperature distribution and current distribution of the power chip mounted on the ceramic substrate, improving the reliability of the power chip and the power module. In addition, the phase change heat dissipation efficiency of the micro-groove cooling cavity 140 on the ceramic substrate is significantly higher than that of existing metal thermal conductivity, significantly reducing the junction temperature of the power chip. At the same time, it reduces the temperature difference inside the power module, especially between the heat sources of the power chip, effectively reducing hot spot effects, facilitating current sharing among parallel power chips, improving the overall reliability of the power module, and giving the ceramic substrate and power module good temperature uniformity and high thermal conductivity. Thus, the power module can also adapt to the requirements of high load, small space, and low cost operation and production.

[0061] Below, in conjunction with Figure 1 The specific structure of the ceramic substrate in this embodiment is described in detail:

[0062] The thickness of the micro-groove cooling cavity 140 is no greater than the thickness of the second metal layer 130, meaning that the thickness of the micro-groove cooling cavity 140 does not exceed the thickness of the second metal layer 130. The width of the micro-groove cooling cavity 140 ranges from 0.2 to 0.8 mm, and the thickness ranges from 0.1 to 0.4 mm. This allows the micro-groove cooling cavity 140 to be stably positioned on the thin second metal layer 130 without damaging its structure, while also ensuring the circuit and electrical design of the auxiliary area 200 on the first metal layer 110.

[0063] Microgroove cooling cavities 140 are uniformly distributed on the first surface of the second metal layer 130. The shape of the microgroove cooling cavities 140 includes, but is not limited to, a serpentine, rectangular, or combination of shapes. The specific shape and number of microgroove cooling cavities 140 can also be set according to actual needs such as power module requirements and optimization of heat dissipation efficiency. For example, ... Figure 2-5 As shown, when processing a microgroove cooling cavity using two independent second metal layers 130, or when the two second metal layers 130 shown are a single integral metal layer, an electrical clearance is reserved; after forming the auxiliary area, the two second metal layers are formed by etching this electrical clearance, as shown. Figure 2-5 The gap between the two second metal layers shown is an electrical clearance. The number of second metal layers 130 can also be set according to actual needs. Figure 2-5 In this process, on the first surface of each second metal layer 130, there is an independent microgroove cooling cavity 140, and an injection mechanism 150 corresponding to the microgroove cooling cavity 140 is also provided.

[0064] like Figure 2 As shown, on each second metal layer 130, the microgroove cooling cavity 140 is laterally serpentine. (As...) Figure 3 As shown, on each second metal layer 130, the microgroove cooling cavity 140 is longitudinally serpentine in shape. Figure 4 As shown, on each second metal layer 130, the microgroove cooling cavity 140 is in a regular rectangular shape. Figure 5 As shown, on the second metal layer 130 on the left, the microgroove cooling cavity 140 is in a regular rectangular shape. On the second metal layer 130 on the right, the microgroove cooling cavity 140 is in a longitudinal serpentine bend.

[0065] By uniformly distributing micro-trench cooling cavities 140 on the first surface of the second metal layer 130, the heat from the power chip mounted on the ceramic substrate is laterally diffused to almost the entire ceramic substrate plane. Since the pulsating heat pipes formed by the micro-trench cooling cavities 140 have a much higher equivalent thermal conductivity than copper, the lateral thermal resistance is negligible. Therefore, the effective heat transfer area is more than doubled through the micro-trench cooling cavities 140, resulting in a significant reduction in the overall thermal resistance of the power module. Furthermore, the micro-trench cooling cavities 140 can diffuse the traditional one-dimensional heat dissipation method to three-dimensional heat dissipation, significantly improving heat dissipation performance. It also ensures uniform junction temperature distribution and current distribution of the power chip, resulting in high performance and reliability of the power module. In addition, by placing the micro-trench cooling cavities 140 on the first surface of the second metal layer 130 and combining it with multi-layer wiring, the second metal layer 130 is divided into only two parts. The rational design of the micro-trench cooling cavities 140 effectively increases the heat transfer area and significantly improves heat dissipation efficiency.

[0066] Therefore, the micro-groove cooling cavity 140 phase change heat dissipation in this embodiment significantly improves the thermal conductivity of existing metals, and significantly reduces the junction temperature of the power chip. At the same time, it reduces the temperature difference inside the power module, especially between the heat sources of the power chips, effectively reduces the hot spot effect, facilitates current sharing among parallel power chips, improves the overall reliability of the power module, and has good temperature uniformity and high thermal conductivity.

[0067] The injection mechanism 150 protrudes from and penetrates the second surface of the second metal layer 130, and connects to the microgroove cooling cavity 140. The injection mechanism 150 is used to seal the microgroove cooling cavity 140 after the working fluid has been filled, thus forming a pulsating heat pipe within the microgroove cooling cavity 140. The specific location of the injection mechanism 150 can be set according to actual needs, such as... Figure 2-5 As shown.

[0068] The injection mechanism 150 is a hollow three-dimensional structure. The injection mechanism 150 includes an inner hollow three-dimensional structure 151 and an outer three-dimensional structure 152, with the outer three-dimensional structure 152 enclosing the inner hollow three-dimensional structure 151. The shape of the inner hollow three-dimensional structure 151 can be any one of a circle, rectangle, triangle, or polygon, or it can be set according to actual needs. The shape of the outer three-dimensional structure 152 can also be any one of a circle, rectangle, triangle, or polygon, or it can be set according to actual needs. Figure 6 and Figure 7 As shown, each second metal layer 130 is provided with a microgroove cooling cavity 140 and an injection mechanism 150 communicating with the microgroove cooling cavity 140. The internal hollow solid 151 of the injection mechanism 150 is circular in shape, and the external solid 152 is circular in shape, indicating that the injection mechanism 150 is a hollow cylinder.

[0069] The working principle of the microgroove cooling cavity 140 and the injection mechanism 150: The injection mechanism 150 is connected to the microgroove cooling cavity 140. Under a vacuum state inside the microgroove cooling channels, the working fluid is filled into the microgroove cooling cavity 140 through the injection mechanism 150. After filling with the working fluid, the injection mechanism 150 seals the microgroove cooling cavity 140, forming an internally circulating and closed cavity, i.e., a pulsating heat pipe. The working fluid material includes, but is not limited to, coolant and liquid metal. Under the action of its own surface tension, the working fluid forms randomly alternating liquid and gaseous columns within the microgroove cooling cavity 140. During operation, due to heat absorption / release, the liquid and gaseous working fluids expand, compress, and interconvert, forming an oscillating pulsating flow, thus achieving heat transfer. Furthermore, the working fluid absorbs heat and evaporates into a gaseous state in the heated zone within the microgroove cooling cavity 140, i.e., it changes from a liquid to a gaseous state (i.e., a phase change), generating a pressure difference. It then flows to the cooled zone, releasing heat and condensing from a gaseous state back into a liquid state. Finally, it flows back to the heated zone due to its own surface tension, completing the cycle. This ensures a uniform lateral distribution of heat as the working fluid circulates within the microgroove cooling cavity 140. The pulsating heat pipe formed by the microgroove cooling cavity 140 and the working fluid features a coreless design, simple structure, ultra-thin profile, reliability, and resistance to gravity.

[0070] The auxiliary region 200 includes: a first auxiliary insulating layer 210, a first auxiliary conductive layer 220, a second auxiliary insulating layer 230, and a second auxiliary conductive layer 240 located on the second metal layer 130. The first auxiliary insulating layer 210, disposed between the second metal layer 130 and the first auxiliary conductive layer 220, serves for insulation and auxiliary heat conduction. The first auxiliary conductive layer 220, disposed between the first auxiliary insulating layer 210 and the second auxiliary insulating layer 230, serves for conducting power current. The second auxiliary insulating layer 230, disposed above the first auxiliary conductive layer 220, serves for insulation. The second auxiliary conductive layer 240, disposed above the second auxiliary insulating layer 230, serves for conducting control signals and sampling electrical signals, such as control signals from an external MCU (Micro Controller Unit) controller or sampling electrical signals from a signal acquisition device. The auxiliary insulating layer is a ceramic sheet insulating layer, and the auxiliary conductive layer is a metal sheet conductive layer.

[0071] Alternatively, the auxiliary region 200 can be configured to include: a first auxiliary insulating layer 210, a first auxiliary conductive layer 220, and a second auxiliary conductive layer 240 located on the second metal layer 130. Both the first auxiliary conductive layer 220 and the second auxiliary conductive layer 240 are disposed on the first auxiliary insulating layer 210. The first auxiliary conductive layer 220 and the second auxiliary conductive layer 240 are located in the same plane, with the second auxiliary conductive layer 240 disposed within the first auxiliary conductive layer 220. An electrical gap is provided between the first auxiliary conductive layer 220 and the second auxiliary conductive layer 240 to achieve electrical isolation between them. With this structure of the auxiliary region 200, the second auxiliary insulating layer 230 is unnecessary, simplifying the number of layers and circuit design, reducing costs, and improving reliability.

[0072] In the auxiliary region, the ceramic insulating layer and the metal conductive layer are discretely arranged in multiple layers, which facilitates the layout of power chips and the bonding of leads. This eliminates the need for chemical etching of the circuit structure, reduces process manufacturing errors, and improves production convenience. Furthermore, in this embodiment, the conductive layer for conducting power current and the conductive layer for conducting control signals and sampling electrical signals are arranged in layers, allowing different transmission circuits to be arranged on the first auxiliary conductive layer 220 and the second auxiliary conductive layer 240. This reduces interference between transmission circuits and improves current carrying capacity, thermal conductivity, current distribution, parasitic parameters, and anti-interference capability.

[0073] like Figure 6 and Figure 7 As shown, the ceramic substrate in this embodiment further includes a temperature acquisition area 300. The temperature acquisition area 300 is located on the second surface of the second metal layer 130 and is used for temperature acquisition. The temperature acquisition area 300 includes a temperature insulation layer 310 and a temperature sampling metal layer 320. The temperature insulation layer 310 is located on the same plane as the auxiliary area 200. The temperature sampling metal layer 320 is disposed on the temperature insulation layer 310 and is used to connect and mount a thermistor and to perform temperature sampling. This embodiment, through the setting of the temperature acquisition area 300, can monitor the temperature of the ceramic substrate and the power chip disposed on the ceramic substrate in real time, thereby avoiding damage to the ceramic substrate or the power chip due to excessive temperature.

[0074] One or more technical solutions in the embodiments of this utility model have at least the following technical effects or advantages:

[0075] The ceramic substrate of this embodiment includes a functional area and an auxiliary area. The functional area includes a first metal layer, a ceramic layer, and a second metal layer stacked sequentially. A microgroove cooling cavity is provided on the side of the second metal layer that contacts the ceramic layer, and an injection mechanism connected to the microgroove cooling cavity is provided on the side of the second metal layer that does not contact the ceramic layer. The microgroove cooling cavity is used to fill a working fluid. The injection mechanism is used to seal the microgroove cooling cavity, forming a closed cavity. The ceramic substrate of this embodiment achieves the mutual conversion of thermal energy and mechanical energy based on the circulation of the working fluid in the microgroove cooling cavity, obtains work by relying on the state change of the working fluid, and transfers heat through the work done by the working fluid. In this way, the ceramic substrate makes full use of the extremely high heat transfer coefficient brought about by the phase change of the working fluid, and can quickly transfer the heat generated by electronic devices.

[0076] Furthermore, in this embodiment, the ceramic substrate, through the micro-groove cooling cavity, injection mechanism, and pulsating heat pipe formed by the working fluid, can laterally diffuse the heat from the power chip mounted on the ceramic substrate to the entire ceramic substrate plane, significantly increasing the effective heat transfer area. This greatly reduces the thermal resistance of the power module based on the ceramic substrate and also ensures uniform junction temperature distribution and current distribution of the power chip mounted on the ceramic substrate, improving the reliability of the power chip and power module. In addition, the phase change heat dissipation efficiency of the micro-groove cooling cavity on the ceramic substrate is significantly higher than that of existing metal thermal conductivity, significantly reducing the junction temperature of the power chip. At the same time, it reduces the temperature difference inside the power module, especially between the heat sources of the power chip, effectively reducing hot spot effects, facilitating current sharing among parallel power chips, improving the overall reliability of the power module, and giving the ceramic substrate and power module good temperature uniformity and high thermal conductivity. Thus, the power module can also adapt to the requirements of high load, small space, and low cost operation and production.

[0077] Example 2

[0078] like Figure 8 As shown, based on Embodiment 1, the ceramic substrate may further have a microgroove cooling cavity 140 on the first surface of the first metal layer 110, and an injection mechanism 150 connected to the microgroove cooling cavity 140 on the second surface of the first metal layer 110. The first surface of the first metal layer 110 is the surface in contact with the ceramic layer 120, and the second surface of the first metal layer 110 corresponds to the first surface of the first metal layer 110.

[0079] In this embodiment, microgroove cooling cavities 140 are provided on the first surface of the first metal layer 110 and the first surface of the second metal layer 130. The microgroove cooling cavities 140 are used to fill the working fluid. An injection mechanism 150, connected to the microgroove cooling cavities 140, is used to seal the microgroove cooling cavities 140, forming a closed cavity. Thus, in this embodiment, the ceramic substrate achieves the mutual conversion of thermal and mechanical energy based on the circulation of the working fluid within the microgroove cooling cavities 140, obtaining work through the state changes of the working fluid, and transferring heat through the work done by the working fluid. In this way, the ceramic substrate fully utilizes the extremely high heat transfer coefficient brought about by the phase change of the working fluid, enabling rapid heat transfer from electronic devices. Compared to the solution in Embodiment 1, this embodiment has higher heat dissipation efficiency, and the reliability of the ceramic substrate, power chip, and power module is also improved.

[0080] Example 3

[0081] Based on the same inventive concept, the third embodiment of this utility model also provides a power module, such as... Figure 9 As shown, the system includes: a ceramic substrate as described in Embodiment 1 or Embodiment 2, a power chip 410 disposed on the ceramic substrate, power terminals and signal terminals of the power chip 410, an outer frame, a cover plate, and encapsulating adhesive. The power terminals and signal terminals are connected to the power chip 410. The cover plate is also disposed on the outer frame. The ceramic substrate, outer frame, and cover plate form a closed cavity so that the power chip 410 is located within the cavity. The encapsulating adhesive fills the closed cavity. The power terminals and signal terminals pass through the cavity.

[0082] exist Figure 9In this design, power chip 410 is a power semiconductor chip with a topology (such as a half-bridge topology or an H-bridge topology) configured according to actual needs. Examples include IGBT (Insulated-Gate Bipolar Transistor) power chips and FRD (Fast Recovery Diode) power chips. IGBT and FRD power chips are connected in parallel. Alternatively, other triode transistor chips such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) can also be used. The power terminals of power chip 410 include a first power pin 421 and a second power pin 422 located on the left side of the ceramic substrate, and a third power pin 423 located on the right side of the ceramic substrate. The signal terminals include: three lower bridge gate terminals 431, a first lower bridge sampling terminal 432, and a second lower bridge sampling terminal 433 arranged sequentially from top to bottom on the left side of the ceramic substrate; and three upper bridge gate terminals 434, a first upper bridge sampling terminal 435, and a second upper bridge sampling terminal 436 arranged sequentially from bottom to top on the right side of the ceramic substrate. Temperature sampling terminals 437 of two thermistors located in the middle of the ceramic substrate are also included. The power module is a half-bridge power module, an H-bridge power module, or a three-phase full-bridge power module. Power chips 410 can be connected to each other and to terminals via bonding wires.

[0083] In this embodiment, the power module utilizes a micro-groove cooling cavity, an injection mechanism, and a pulsating heat pipe formed by the working fluid to laterally diffuse the heat from the power chip across the entire ceramic substrate plane, significantly increasing the effective heat transfer area. This greatly reduces the thermal resistance of the power module and ensures uniform junction temperature distribution and current distribution of the power chip, improving the reliability of both the power chip and the power module. Furthermore, the phase-change heat dissipation efficiency of the micro-groove cooling cavity is significantly higher than that of existing metal thermal conductivity, substantially reducing the junction temperature of the power chip. Simultaneously, it reduces the temperature difference within the power module, especially between the heat sources of the power chip, effectively minimizing hotspot effects, facilitating current sharing among parallel power chips, and enhancing the overall reliability of the power module. This results in excellent temperature uniformity and high thermal conductivity for both the ceramic substrate and the power module.

[0084] Those skilled in the art will understand that although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0085] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A ceramic substrate, characterized in that, include: A functional area and an auxiliary area, wherein the auxiliary area is disposed on the functional area; The functional area includes: a first metal layer, a ceramic layer and a second metal layer stacked in sequence; a microgroove cooling cavity is provided on the first side of the second metal layer; and an injection mechanism connected to the microgroove cooling cavity is provided on the second side of the second metal layer. The first side of the second metal layer is the side of the second metal layer that contacts the ceramic layer, and the second side of the second metal layer is correspondingly arranged with the first side of the second metal layer. The auxiliary region is used for conducting current and signals; The microgroove cooling cavity is used to fill the working fluid so that the microgroove cooling cavity can achieve the function of heat dissipation; The injection mechanism is used to seal the microgroove cooling cavity.

2. The ceramic substrate as described in claim 1, characterized in that, The thickness of the microgroove cooling cavity is no greater than the thickness of the second metal layer, and the microgroove cooling cavity is uniformly distributed on the first surface of the second metal layer.

3. The ceramic substrate as described in claim 2, characterized in that, The width of the microgroove cooling cavity ranges from 0.2 to 0.8 mm, and the thickness ranges from 0.1 to 0.4 mm.

4. The ceramic substrate as described in claim 1, characterized in that, The injection mechanism protrudes from the second surface of the second metal layer, penetrates the second metal layer, and is connected to the microgroove cooling cavity.

5. The ceramic substrate as described in claim 4, characterized in that, The injection mechanism includes an internal hollow three-dimensional structure and an external three-dimensional structure, wherein the external three-dimensional structure encloses the internal hollow three-dimensional structure.

6. The ceramic substrate as described in claim 1, characterized in that, The auxiliary region includes: a first auxiliary insulating layer, a first auxiliary conductive layer, a second auxiliary insulating layer, and a second auxiliary conductive layer located on the second metal layer; The first auxiliary insulating layer is disposed between the second metal layer and the first auxiliary conductive layer, and is used for insulation and auxiliary heat conduction; A first auxiliary conductive layer is disposed between the first auxiliary insulating layer and the second auxiliary insulating layer for conducting power current; The second auxiliary insulating layer is disposed on the first auxiliary conductive layer and is used for insulation; The second auxiliary conductive layer is disposed on the second auxiliary insulating layer and is used to conduct control signals and sampling electrical signals.

7. The ceramic substrate as described in claim 1, characterized in that, The auxiliary region includes: a first auxiliary insulating layer, a first auxiliary conductive layer and a second auxiliary conductive layer located on the second metal layer; Both the first auxiliary conductive layer and the second auxiliary conductive layer are disposed on the first auxiliary insulating layer. The first auxiliary conductive layer and the second auxiliary conductive layer are located on the same plane. The second auxiliary conductive layer is disposed within the first auxiliary conductive layer. An electrical gap is provided between the first auxiliary conductive layer and the second auxiliary conductive layer to achieve electrical isolation between the first auxiliary conductive layer and the second auxiliary conductive layer.

8. The ceramic substrate as described in claim 1, characterized in that, Also includes: A temperature acquisition area, located on the second surface of the second metal layer, is used to acquire temperature. The temperature acquisition area includes: a temperature insulation layer and a temperature sampling metal layer; The temperature insulation layer is located on the same plane as the auxiliary area; The temperature sampling metal layer is disposed on the temperature insulation layer and is used to connect and install the thermistor and to perform temperature sampling.

9. The ceramic substrate according to any one of claims 1 to 8, characterized in that, The first metal layer has a microgroove cooling cavity on its first surface and an injection mechanism connected to the microgroove cooling cavity on its second surface. The first surface of the first metal layer is the surface in contact with the ceramic layer, and the second surface of the first metal layer is correspondingly disposed to the first surface of the first metal layer.

10. A power module, characterized in that, include: The ceramic substrate as described in any one of claims 1-9, and the power chip disposed on the ceramic substrate, the power terminals and signal terminals of the power chip, the outer frame, the cover plate and the encapsulating adhesive, wherein the power terminals and the signal terminals are connected to the power chip; The cover plate is also disposed on the outer frame, and the ceramic substrate, the outer frame and the cover plate form a closed cavity so that the power chip is located in the cavity; The encapsulating adhesive fills the sealed cavity; The power terminal and the signal terminal pass through the cavity.

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